Ken'ichi Ohmichi wrote:> Hi,> > This patch enables a kdump if 2nd-kernel is loaded.> (The patch is based on linux-2.6.31-rc2.)> > Now, a kdump is enabled if a kernel parameter "oops=panic" is specified and> 2nd-kernel is loaded. I think that a kdump should be enabled regardless of> "oops=panic" if 2nd-kernel is loaded, because a system administrator loads> 2nd-kernel for enabling a kdump.

I think this description is slightly wrong because kdump will be invokedfrom panic, regardless of the panic_on_oops.

>> I tried to test a kdump on linux-2.6.31-rc1 *without* a kernel parameter>> "oops=panic" by `echo c > /proc/sysrq-trigger`, but a kdump did not work>> because a kdump, which is occurred by `echo c > /proc/sysrq-trigger`, has>> been changed to a NULL pointer error instead of calling crash_kexec()>> since linux-2.6.31-rc1.

So the real problem is that kdump is not triggered by the NULL pointer oopsif !panic_on_oops, isn't it?

It seems that you should report this trouble of sysrq-c as a regression.

since crash_kexec() is nop if !kexec_crash_image, replace all: if (kexec_should_crash(p)) crash_kexec(reg); at everywhere in kernel to a simple line: crash_kexec(reg); and remove kexec_should_crash() completelywould be better fix.